This invention relates to a selective access closure device inside a catheter of the type comprising a body bounding a conduit having a rear extremity into which a medical instrument is inserted and a front extremity provided with means for connection to the catheter and also a mechanism for adjusting the passage cross-section within the conduit, this adjustment mechanism comprising a device to reposition means which can move with respect to the body along an opening path to bring about a change to an open condition in which a nominal passage cross-section is provided within the conduit and a closing path to bring about a change to a closed condition in which passage through the conduit is at least partly obstructed.
Such a device is in particular used in angioplasty procedures performed in cardiology. These procedures comprise shaping a blood vessel (vein or artery) which has become constricted, causing a reduction in blood flow. This shaping of the vessel is effected either through mere dilation of the vessel using an inflatable balloon or the fitting of a self-expanding tubular endoprosthesis currently known as a “stent”.
Whatever the nature of the procedure, it is advantageous to act within the patient's circulatory system. For this purpose an incision is made in an artery, generally the femoral artery, and a catheter is inserted into it. The various instruments required for treating the vessel are delivered to the location for the procedure through travel within the circulatory system after having been inserted via the indwelling catheter in the femoral artery. More specifically a surgical guide comprising a long flexible metal wire, a balloon, a stent or another catheter may be inserted into the circulatory system through the prefitted catheter. In order to avoid excessive bleeding from the patient the catheter inserted in the femoral artery is provided at its free end with a selective closure device which will prevent the outflow of blood while making it possible for the various instruments necessary for the procedure to be inserted in the catheter.
Selective closure devices are already known. They generally comprise a diaphragm obstructing the passage provided within the body of the device. This diaphragm comprises for example an elastic seal. The device comprises an appropriate mechanism to cause deliberate opening of the seal in order to allow the instruments necessary for the procedure to be inserted. This mechanism generally comprises a sliding tubular member which can be moved between a position away from the seal and a position engaging the inner part of the seal, thus increasing its inner cross-section. The tubular member can for example be moved in lateral movement under the control of a rotating ring or a sliding cursor. The ring or cursor can be moved in one direction to bring about opening of the device and in the other direction to cause its closure.
Such a device is inconvenient to operate because the surgeon must use both hands, one to hold the body of the device and the other to move the ring or cursor.